The Starrett 440, 440M, 445, 445M Series Depth Micrometer Features A Combination Ratchet And Speeder, Ring-Type Locknut, Ratchet Stop And Locknut. 0-150Mm Range, 63.5Mm Base, 6 Rods, Ratchet Stop, Lock Nut, Case.

• The depths of holes, slots, shoulders and projections can be measured with these fine tools
• 63.5mm (2-1/2") base and 3.2mm (1/8") diameter measuring rods
• Combination ratchet and speeder for uniform pressure and quicker adjustment
• Ring-type knurled lock nut for quick and sure locking